1. Field of the Invention
Hydrogen cyanide is produced when an organic nitrile is reacted with hydrogen at 400.degree.-700.degree. C. in the presence of selected catalysts. The process is a hydrodecyanation reaction as shown by the reaction EQU RCN + H.sub.2 .fwdarw. RH + HCN
where R is a hydrocarbon radical such as phenyl.
2. Prior Art
Krebaum, U.S. Pat. No. 3,371,990 reacts an organic nitrile with hydrogen at 600.degree.-850.degree. C. in the absence of any catalyst and obtains hydrogen cyanide. The efficiency of this process is low.
Walker, U.S. Pat. No. 2,702,815 heats benzonitrile alone at temperatures of 500.degree.-1000.degree. C. to obtain a mixture of phthalonitriles. Hydrogen cyanide, benzene and other materials are obtained as by-products and the efficiency of this process is also low.
Arnold et al., U.S. Pat. No. 2,584,531 hydrogenate an organic compound such as benzonitrile in the presence of a catalyst comprising a metal molybdite. The products obtained are benzylamine and 2,4,5-triphenylimidazole.
Cass, U.S. Pat. No. 2,867,628 hydrogenates an organic compound at ambient temperature in the presence of palladium. Toluene is the product obtained when benzonitrile is used.
Rylander et al., U.S. Pat. No. 3,177,258 hydrogenates an organic compound at 0.degree.-350.degree. C. in the presence of a ruthenium metal catalyst. The products are stated to be mixtures of amines when a nitrile is used.
Sperka, U.S. Pat. No. 3,658,471 prepares HCN from acetonitrile and ammonia using a platinum group metal catalyst at elevated temperatures of 1100.degree.-1400.degree. C.